After over a decade in development, Mac OS X is on sale! Now! As of midnight Saturday, March 24, customers can buy Mac OS X in stores around the world. But, a word of warning, this initial release is meant for brave, early adopters only. It’s missing some key features, and may still include some bugs. An update is expected at July’s Macworld Expo in New York, which will add any missing features and cure remaining bugs. Smaller updates, however, can be expected every few weeks from now.

Mac OS X (which ships with a copy of OS 9.1 for dual-boot capability) is available through The Apple Store and through Apple Authorised Resellers for £99 (inc. VAT).

Apple needs to get Mac OS X out on the market because it has been so very long in coming. The operating system that currently ships on Macs is a direct descendant of the OS that ran the first 128K Macintoshes Apple sold in 1984; for the past 17 years, Apple's OS development has been evolutionary, rather than revolutionary. Apple committed to revamping its venerable OS in 1994, a decision spurred in part by a similar project from Microsoft. But while Redmond's efforts bore fruit only a year later with Windows 95, Apple's project meandered on for better than half a decade. A major change in direction occurred in December 1996, when Apple bought NeXT, and company founder Steve Jobs reassumed control; much of the intellectual property Jobs brought over from NeXT found its way into OS X.

Modern functionality Mac OS X is Apple’s totally re-engineered Macintosh operating system that boasts modern features that Apple claims makes it “the world's most advanced operating system”.

OS X’s protected memory architecture isolates applications in their own memory space, so you don’t need to restart your computer if something goes wrong. OS X’s Darwin core simply shuts down the offending application, letting you continue working or playing without interruption.

Pre-emptive multitasking means you can still check email, work in another application or surf the Web while processing another task in the background.

A Virtual Memory Manager means you no longer have to worry about how much memory an application requires. When an application needs memory, the Virtual Memory Manager automatically allocates precisely the amount needed by the application.

OS X offers built-in support for dual-processor Power Mac G4 computers. The operating system allows the user to use one processor to run, say, a complex image transformation and the other to encode a new MP3 file. In addition, all applications benefit from the higher performance a second processor offers. Apple claims that multithreaded programs can run “almost twice as fast” using Mac OS X on a dual-processor Power Mac G4.

Support for Java 2 Standard Edition is built directly into Mac OS X,
giving customers access to cross-platform applications – such as those from Oracle.

X revolution Mac OS X also features an entirely new customisable user interface called Aqua, which includes the Dock for organizing documents, applications and windows.

"Mac OS X is the most important software from Apple since the original Macintosh operating system in 1984 that revolutionised the entire industry," said Steve Jobs, Apple's CEO. "We can't wait for Mac users around the globe to experience its stability, power and elegance."

Optimized apps Apple claims that over 350 applications for Mac OS X are shipping, with hundreds more coming by this summer. More than 10,000 developer organisations around the world are working on over 20,000 Mac OS X applications, including 4D, Aladdin Systems, Alias/Wavefront, Avid, Connectix, Dantz, Digidesign, EarthLink, FileMaker, IBM, Macromedia, Microsoft, MYOB, Palm, Sun, Symantec and Thursby Software Systems.

Apple will also ship Mac OS X versions of its three most popular applications on March 24, available as free downloads.

Mac OS X features Apple's new Quartz 2D graphics engine (based on the Internet-standard Portable Document Format) for enhanced graphics and broad font support. OpenGL supports professional 3D graphics and gaming. And QuickTime 5 is there for streaming audio and video.

Compatibility Mac OS X requires a minimum of 128MB of memory, and is designed to run on any G3 or G4 Apple Macintosh – except the original PowerBook G3 (bought before May 1998).